1. Field of the Invention
The present invention relates to a test emulator, an emulation program and a method of manufacturing a semiconductor device. Particularly, the present invention relates to a test emulator for emulating a test of a semiconductor device, an emulation program and a method of manufacturing a semiconductor device.
2. Related Art
Recently, semiconductor devices such as VLSIs are designed in hardware description language (HDL) such as Verilog-HDL and VHDL using computers. Such design in HDL is verified whether a function intended by the designer is performed using a simulator (Verilog-HDL/VHDL simulator) at behavioral level and gate level before it is manufactured as a silicon IC.
For example, a technology for emulating a test of a semiconductor device by a semiconductor test apparatus to verify the design of the semiconductor device has been disclosed as disclosed, for example, in Japanese Patent Unexamined Publication No. 2002-215712.
However, the semiconductor device used in the emulated test is merely an ideal device of which behavior is simulated based on the HDL. Accordingly, the test result of the simulated semiconductor device may not correspond to that of an actual semiconductor device. The test result of the simulated semiconductor device may not correspond to that of an actual semiconductor device even if output signals are compared with a reference value at the same timing as each other because the leading timing of the output signal of the simulated semiconductor device is different from that of the actual semiconductor device or and the leading edge of the output signal of the actual semiconductor device is not sharp. That is to say, the simulated semiconductor device has passed the emulated test, but the semiconductor device manufactured as the silicon IC may not pass a test conducted by the semiconductor test apparatus.
To emulate a test using a simulator based on the HDL is essentially expected an effect to manufacture semiconductor devices at lower cost without repeatedly manufacturing experimental chips and modifying the design. However, since the accuracy of the emulated test has not been sufficient before, any satisfactory effect has not been obtained.